Automatic telephone dialing systems, such as the MOSAIX PREDICTIVE DIALING SYSTEMS offered by AVAYA INC., Basking Ridge, N.J., are widely used at customer call centers. The SYSTEMS are also used at other businesses to automate outbound contacts for collections, telemarketing campaigns and proactive customer services. For applications such as telemarketing campaigns, automatic dialing systems may be coupled with interactive voice response (“IVR”) systems such as AVAYA's INTUITY™ CONVERSANT® SYSTEM. An IVR system, generally, presents recorded voice information to the outbound contact (“called party” or “destination”). The IVR system may also elicit voice information from the destination in order to complete a transaction. If, however, the IVR system for any reason cannot complete a transaction, it may transfer the destination to a live agent better equipped to serve the destination. In the event that the automatic dialing system reaches an answering system rather than a live person answering the call, it would be desirable to disengage the IVR system and terminate the call.
One approach for addressing this need employs a tone based detection scheme, commonly found in current IVR systems. This scheme allows an IVR system to listen for a special tone generated by a machine such as an answering machine. This tone usually has high energy concentration on a narrow band of frequencies, for example, one or two frequencies, in the range from 1 KHz to 2 KHz. Generally, when the tone is detected, the IVR system determines that the destination is a machine, halts the communication and instructs the automatic dialing system to terminate the call.
A disadvantage of this approach is that some answering machines do not generate a special tone. Furthermore, tone based interface is not a standard, and the tone has often been replaced by more user friendly interfaces selected or designed to fit each individual's liking. Consequently, when the interface changes, an IVR system may falsely identify the destination as not a machine. With that false identification, the IVR, generally, continues to hold the call or transfers the call to a live agent resulting in inefficient use of the IVR resources or the live agent.